If time is a river, the Histomap, created by John B. Sparks and first published by Rand McNally back in 1931, is a raging Mississippi. In that massive river of time, each of humanity’s great civilizations becomes a confluence that ebbs, wanes, and sometimes ebbs again, each a separate current in a river that inexorably rages down to the mouth of the present day.

Although certainly not modern, the Histomap is still a breathtaking example of good infographic design: A five-foot, roll-up chart that can fit an overview of human history on any wall. Starting in 2000 B.C. with seven different civilizations—the Aegeans, the Egyptians, the Hittites, the Amorites, the Iranians, the Indians, the Huns, and the Chinese—you travel forward or backward in time as your eyes move up or down 0.75 inches. Some civilizations bleed together, others are swallowed up; some surge, others crash.

While the X-axis indicates time in Sparks’ Histomap, the Y-axis appears to indicate the size of each empire. Although time is a remarkably objective data point for this kind of infographic, and so the length of each civilization’s journey section of the Histomap is easy to interpret, it’s less clear exactly what Sparks was trying to say with each civilization’s waxing and waning width. Is the girth of a civilization determined by the number of its subjects? Its geopolitical influence? Its sheer sprawl across the globe? The size of its military? Its contribution to the arts and sciences? Its wealth? Unfortunately, Sparks isn’t around anymore to tell us.

From a modern perspective, Sparks’ Histomap will raise a few eyebrows. For one, it subscribes to an outdated (but, at the time, quite in vogue) idea about how different cultures throughout history could be grouped into various "peoples." The chart also underestimates or omits certain cultures that historians at the time didn’t truly appreciate the importance of. The chart is also more Eurocentric than it would be if it were created today, with little space devoted to African civilizations or even American civilizations before Europeans settled the New World in the 15th century.

As a look at what historians at the time thought about the course of history, though, it’s easy to forgive Sparks’ Histomap for not being ahead of its time. It’s a laudable achievement. According to Rebecca Onion over at Slate, in the 1920s and 1930s, charts that even a layman could understand which tried to encapsulate huge schools of knowledge (like philosophy, history, medicine, science, and physics) were extremely popular. Sparks’ Histomap is a perfect example of how, even the better part of a century ago, designers were using infographics to make complicated, head-dizzying data sets not just relatable but intimately familiar to everyone, no matter what their educational background.

Sparks didn’t stop at the Histomap of Human Civilization. Unbelievably, he created an even more epic Histomap of Evolution. If you think watching civilizations try to squeeze each other out of the picture over the course of 4,000 years is epic, imagine when that battle of survival is waged between different species over the course of hundreds of billions of years.